Units of derivatives in the variables browser

[Francesco Casella]

Currently, if a certain variable v has the attribute unit = "u", then also its time derivative is displayed with the same unit "u". Of course it should be "u/s".

[Adeel Asghar]

The problem is in the model_init.xml file which is used by OMEdit to get the unit values.

[Lennart Ochel]

This is a basic error. Currently, time is treated without any unit, but it has to be in "s".

[Martin Sjölund]

This ticket was not closed for 1.9.1, which has now been released. It was batch modified for milestone 1.9.2 (but maybe an empty milestone was more appropriate; feel free to change it).

[Martin Sjölund]

Milestone changed to 1.9.3 since 1.9.2 was released.

[Martin Sjölund]

Moved to new milestone 1.9.4

[Francesco Casella]

Please have this issue fixed asap, it should be very straightforward:

• the predefined variable time should have quantity = "Time" and unit = 's', see Modelica Language Specification, section 3.6.7
• all derivatives with respect to time should have s^-1 added to their unit

[Martin Sjölund]

Milestone pushed to 1.9.5

[Martin Sjölund]

Milestone renamed

[Francesco Casella]

The situation has slightly improved, in the sense that now no unit at all is displayed in the variable browser. This is better than having the wrong unit, but it would be good to have the right one in place.

[Lennart Ochel]

Replying to casella:

The situation has slightly improved, in the sense that now no unit at all is displayed in the variable browser. This is better than having the wrong unit, but it would be good to have the right one in place.

Sure, I just removed the wrong units in a first step, because that was easy. I will adapt the back end unit module to provide the right units.

[Lennart Ochel]

​OMCompiler#881 provides unit information for state derivatives.

[Francesco Casella]

It seems there are still some problems left.

Try simulating Modelica.Mechanics.Translational.Examples.Dampers. Some differentiated variables, e.g., damper1.der(s_l) now have the correct unit, some others, e.g., mass1.der(s) are still left without any unit.

[Martin Sjölund]

Ticket retargeted after milestone closed

[Martin Sjölund]

Milestone moved to 1.12.0 due to 1.11.0 already being released.

[Francesco Casella]

Milestone moved to 1.13.0 due to 1.12.0 already being released.

[Christoph Buchner <buchner@…>]

I just checked with a recent 1.13 dev version, and the situation from comment:12 is still present (although it's damper1.der(s_rel), not s_l).

[Francesco Casella]

Replying to Christoph Buchner <buchner@…>:

I just checked with a recent 1.13 dev version, and the situation from comment:12 is still present (although it's damper1.der(s_rel), not s_l).

The problem is still there as of OMEdit v1.13.0-dev-115-ga31e9070 (64-bit).

@adeas31, can you please have a look?

[Adeel Asghar]

Its still the problem of unit module. The model_init.xml contains,

<ScalarVariable
    name = "der(damper1.s_rel)"
    valueReference = "1006"
    description = "der(Relative distance (= flange_b.s - flange_a.s))"
    variability = "continuous" isDiscrete = "false"
    causality = "internal" isValueChangeable = "false"
    alias = "noAlias"
    classIndex = "0" classType = "rDer"
    isProtected = "false" hideResult = "false"
    fileName = "C:/OpenModelica/build/lib/omlibrary/Modelica 3.2.2/Mechanics/Translational.mo" startLine = "4687" startColumn = "7" endLine = "4690" endColumn = "75" fileWritable = "true">
    <Real fixed="false" useNominal="false" unit="m.s-1" />
  </ScalarVariable>

For der(damper1.s_rel) the unit information is available.

<ScalarVariable
    name = "der(mass1.s)"
    valueReference = "1017"
    description = "Absolute position of center of component (s = flange_a.s + L/2 = flange_b.s - L/2)"
    variability = "continuous" isDiscrete = "false"
    causality = "internal" isValueChangeable = "false"
    alias = "noAlias"
    classIndex = "5" classType = "rAlg"
    isProtected = "false" hideResult = "false"
    fileName = "C:/OpenModelica/build/lib/omlibrary/Modelica 3.2.2/Mechanics/Translational.mo" startLine = "4622" startColumn = "7" endLine = "4623" endColumn = "93" fileWritable = "true">
    <Real fixed="false" useNominal="false" />
  </ScalarVariable>

For der(mass1.s) the unit attribute is missing.

[Francesco Casella]

@mahge930 used to work on this, but I get he's now 100% busy with his PhD work. Anyone else can fix this?

[Mahder Alemseged Gebremedhin]

Sorry I am late to this. I will take a look.

[Francesco Casella]

Thank you @mahge930!

[Francesco Casella]

Rescheduled to 1.14.0 after 1.13.0 releasee

[Francesco Casella]

@mahge930, any chance you can fix this issue now, in time for the 1.14.0 release?

Thanks!

[Francesco Casella]

Releasing 1.14.0 which is stable and has many improvements w.r.t. 1.13.2. This issue is rescheduled to 1.16.0

[Francesco Casella]

Retargeted to 1.17.0 after 1.16.0 release

[Francesco Casella]

Retargeted to 1.18.0 because of 1.17.0 timed release.

[Francesco Casella]

Ticket retargeted after milestone closed